Electrical fuse-plug.



H. E; BRADLEY.

ELECTRICAL FUSE PLUG.

ICATION FILED Patented. Nov.'24', 190s.

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HAROLD E. BRADLEY, OF GREENWOOD, RHODE ISLAND, ASSIGNOR OF ONE-HALF TOMARION O. HAPPOLDT, OF PROVIDEN OE,JRHODE ISLAND.

g 'ELEorRIcA FUSE-PLUG.

Specification of Letters Patent.

Patented Nov. 24,1908.

I Application filed January 3,1908. Serial No. 409,181.

To all whom it may concern:. I

Be it known'that I, HAROLD E. BRADLEY, a citizen of the United States,residing at Greenwood, in the county of Kentand Stateof RhodeIsland,-have invented certain new and useful Improvements in ElectricalFuse- Plugs, of which the following is a specification, reference beinghad therein to the accompanying drawing. 7 v

My invention relates to electric fuse plugs.

of the class constructed with'a fuse cartridge 'removably held in acasing,'and has for its object to. provide a simple/and effective meanswhereby the cap for the case is pre vented from being inadvertently.remo'ved therefrom before said case has been removed from its supportor cut-out block.

In the practical use of fuses of this char-- acter the cartridge isfirst inserted into its casing, the cap (which is of insulating ma.-terial'),-is screwed-onto the upper endrofthe casing, and said casing isthen screwed into its block. WVhen the cartridge-has blown and y it isdesired to remove andreplace the fuse the cap, which forms a convenienthandle, is naturallygrasped by the hand and turned backwards in order tounscrew the case from said block, but in most instances the cap itself,which is only held by the friction of the screw-thread, will be thefirst to unscrew and come off, leaving the case still in position and incircuit. The operator usually then tries toremove the cartridge from thecase, whereupon he is almost certain to receivea shock, which is, tosaythe least, very unpleasant and in some caseslwhere a heavy voltage isused, might prove fatal.

To obviate the above di'fiiculty I have pro vided a lock forautomatically connecting the-cap to the casing when said cap is appliedthereto. The form of lock, asv illustrated in the drawin s, consistsessentially in a spring tongue or ip on the casing as being adapted toengagda lug or tooth on the cap bywhich the two parts may be auto--matically locked together. -After the casing has been backed outof itsblock a slight pressure of the thumb or finger on this tongue at oncereleases the lock and the cap maybe removed from its casingexposing thecartridge which may then be removed and re.-

placed without the slightest inconvenience or danger.

With these objects in view, the invention consistsjoficert'ain, novelfeatures of con-- struction, aswill'be more fully described andparticularly pointed out in the appended claims. I

In the accompanying drawings: Figure l-is a side', elevati'on showingthe cap in 2 of the casing 3. This casing is usually made with: an outershellof'brass or other conducting material and lined with an in sulatingbushing 4. The lower end 5 is provided with a contact button which makesan electricconnection through the plate 6 in the cut-out block to theterminal 8. The upper end of this casing is also threaded as at 7 ontowhich the cap 10, which is preferably; made of insulating material, isdesigned to screw. The capis provided with a lining of conductingmaterial.' Into this casing is loosely fitted the fuse cartridge 11-which may be made in the usual 'form now on the market the circuit assinfrom terminal 8 through button 6, cartridge 11, casing 3- and terminal9. I

improvem'entconsists 1n the construc- -tion.of a locking device forconnecting the position on th-efcasing and the spring tongue engagingone'mfthe lugs on said cap. Fig.

cap to its casing. Locking devices for this purpose may be constructedin many different ways but I have'shown one simple and effective waywhich consists in cutting a strip of metal from the bod-yer the casingleaving zone end integral therewith, and raising the opposite end of thesame forming a spring tongue 12, best illustrated in Fig. 3. I also formone or more teeth or lugs 1313 projecting from the inner end of the cap,which teeth, are adapted to engage, depress and 'pass over said springtongue as the cap is being screwed onto the casing. but when said cap isturned in the opposite direction one of the teeth will naturally comeinto contact with the end of said tongue and prevent the cap frombeingunscrewed until the tongue proved attachment.

40 cap from said casing.

Q see-s32 10 the same, the hand naturallygrasps the in sulated cap andturns the same back on the casing until one of the lugs brings upagainst the spring tongue whereupon the casing is unscrewed from 1tscut-out block, after which the little spring tongue is depressed by thethumb or finger of the operator and the cap at once removed. The cartricge may then be taken out and replaced completely obviating anypossibility of receiving a v shock during the operation 1 I have shownand described a lock which conslst-s essentially of a spring lip ortongue adapted to engage one or more correspond,

ing projections on the cap, but I do not confine myself to thisparticular construction of a lock, as any means for preventing the acci-\dental removing of said cap from said case will come within the spiritand scope of my invention.

Haying thus described my invention, what I claim as new and desire tosecure by Letters Patent, is: p 1. An improvement in fuse plugs comprising a casing constructed to receive a fuse, a

cap engaging one end of said casing, and means for locking said cap tosaid casing,

said -locking means being exposed below said cap, whereby the same maybe manipulated manually to effect the disengagement of said 2. Animprovement in fuse plugs comprising a casing constructed to receive afuse, cap engaging one end of said casing, l

and 1 means termed integral with the casing for locking said cap to thecasing, said locking means being exposed below said cap, where y thesame may be manipulated manually.

S. An improvement in fuse plugs comprising a casing constructed toreceive a fuse, a cap engaging one end of said casing, and a spring guefor locking said cap to said ca sing srzltl tongue being exposed belowcap, whereby the same may be manipulated manually.

d. An improvement in fuse plugs comprising a casing constructed toreceive a fuse and provided with an exterior threaded portion, a capengaging said threaded portion, and means for locking said cap to saidcasing, said locking means being exposed below said cap, whereby the.same may be manipulated manually.

5. An improvement in fuse plugs comprising a casing constructed toreceive a fuse and provided with an exterior threaded portion, athreaded capengaging said threaded portion, and a spring tongue arrangedto pievent reverse movement of said cap, said tongue bein g exposedbelow the cap, whereby the same may be manipulated manually.

6. An improvement in fuse plugs comprising a casing provided with ascrew thread at each end, .a spring tongue being formed in tegral withsaid casing and located intermediate of said ends, a cut out blockthreaded to receive one of said ends, and a threaded cap constructed toengage the other threaded end and provided with means for engaging saidtongue, said tongue being located below said cap.

" In testimony whereof I afix my signature in presence of two witnesses.

HAROLD E. BRADLEY. Witnesses How-Venn E. BARLOW, E. I. OGDEN.

